| Skylift Platforms Ltd. | Construction | 2019 |
| Skyrus Ltd | Extraterritorial | 2022 |
| SL Sports Ltd | Arts & recreation | 2009 |
| SLC Builders and Consultants Limited | Construction | 2009 |
| Sleep-Pro Limited | Wholesale & retail | 2008 |
| Slim Gym Training Equipment Limited | Wholesale & retail | 2015 |
| Small Torque Garages Ltd | Wholesale & retail | 2026 |
| Smart City Consultancy Limited | Information & communication | 2013 |
| Smbi Limited | Real estate | 2017 |
| Smile Kind Limited | Health & social care | 2012 |
| Smith Whitty International Consultants Limited | Health & social care | 1985 |
| Social and Care Consulting Ltd | Health & social care | 2015 |
| Social ETC. Ltd | Professional & scientific | 2023 |
| SOL House Northampton Limited | Construction | 2025 |
| SOLV3 Engineering Limited | Professional & scientific | 2018 |
| Something Less Boring Ltd | Education | 2021 |
| Sonata Developments Limited | Construction | 2017 |
| Sorbus Rural Ltd | Agriculture & fishing | 2021 |
| Sorrentino Pasta House Limited | Hospitality | 2008 |
| SOS Supercar Club Ltd | Other services | 2024 |
| Sosaia Ltd | Wholesale & retail | 2025 |
| Soultree Holdings Ltd | Real estate | 2018 |
| Soundfirm Limited | Administrative & support | 2005 |
| Source UK Inc Ltd | Administrative & support | 2012 |
| Southampton Airport and Cruise Transfers Ltd | Transport & logistics | 2026 |
| Southgate Global Services Ltd | Construction | 2010 |
| Sparkbit Limited | Professional & scientific | 2016 |
| Sparkle Group Ltd | Wholesale & retail | 2015 |
| Specialist Property Accountants Ltd | Professional & scientific | 2007 |
| Spherical 360 Publishing Limited | Information & communication | 2020 |
| Spicymadras Ltd | Hospitality | 2024 |
| Spinnaker Carpet Care Limited | Administrative & support | 2013 |
| Spinnaker Carpet Cleaning Ltd | Administrative & support | 2026 |
| Spinnaker Holdings Limited | Administrative & support | 2024 |
| Splash Rentals Ltd | Wholesale & retail | 2024 |
| Splinters Wood Recycling C.I.C. | Water & waste | 2020 |
| Sports Blast Limited | Arts & recreation | 2024 |
| Spot TV Limited | Information & communication | 2024 |
| Spring Lane (Stagsden) Management Company Limited | Households | 2022 |
| Springclean 91 Limited | Administrative & support | 2015 |
| SRM Specialised Risk Management Ltd | Administrative & support | 2015 |
| SSJ Holdings Limited | Financial services | 2008 |
| ST Luke's Court (Falcon Road) Management Company Limited | Households | 2003 |
| ST Margarets CT a Leaseholders RTM Company Limited | Households | 2025 |
| ST Margarets CT B Leaseholders RTM Company Limited | Households | 2025 |
| ST Margarets CT C Leaseholders RTM Company Limited | Households | 2025 |
| ST Margarets CT Leaseholders RTM Company Limited | Households | 2025 |
| ST. Elmo Care Ltd | Health & social care | 2020 |
| STA Coach Tours Ltd | Transport & logistics | 2018 |
| Starbucks Coffee Burger King Limited | Professional & scientific | 2010 |
| Starbucks Coffee KFC Limited | Professional & scientific | 2010 |
| Starbucks Coffee Mcdonald's Limited | Professional & scientific | 2010 |
| Starbucks Coffee Mcdonald's Waitrose Limited | Professional & scientific | 2011 |
| Starbucks Coffee Waitrose KFC Limited | Professional & scientific | 2011 |
| Starbucks Coffee Waitrose Limited | Professional & scientific | 2010 |
| Startspirit (MK) Limited | Administrative & support | 2017 |
| Stebles Property Ltd | Administrative & support | 2012 |
| Steelwise Limited | Construction | 2011 |
| Stellar Demolition Ltd | Construction | 2026 |
| Steph the Barber - Private Barbering Ltd | Other services | 2021 |
| Stepping Stones NS Limited | Education | 2020 |
| Steve Sprange Enterprises Ltd | Other services | 2021 |
| Steve Wood Consulting Limited | Professional & scientific | 2017 |
| Stevenson Corporate Venture Limited | Real estate | 2014 |
| Stimson & Co Limited | Agriculture & fishing | 2013 |
| Stingeys Ltd | Hospitality | 2020 |
| Stixx Digital Limited | Information & communication | 2019 |
| Stoke Goldington Allotment Association CIC | Agriculture & fishing | 2023 |
| Stoke Goldington VH Ltd | Hospitality | 2026 |
| Stonevale Developments Ltd | Construction | 2024 |
| Storm Creative Design Limited | Professional & scientific | 2008 |
| Storytrek Limited | Information & communication | 2019 |
| Strategic Evolution Limited | Professional & scientific | 2010 |
| Stratos Production Limited | Hospitality | 2024 |
| Stratton Oak Properties Limited | Real estate | 2022 |
| Stride Mortgages Limited | Administrative & support | 2019 |
| Stronghold Homes (Bletchley) Limited | Extraterritorial | 2021 |
| Stronghold Property Limited | Construction | 2015 |
| Stuart Lovell Services Limited | Administrative & support | 2024 |
| Student Recruiting Ltd | Education | 2021 |
| Studio 43 Ltd | Professional & scientific | 2010 |
| STUDIO25 Ladies Only Fitness Ltd | Arts & recreation | 2025 |
| Stylishrooms Ltd | Real estate | 2016 |
| Subconsciously Well Being Services Ltd | Health & social care | 2019 |
| Subtrend Limited | Professional & scientific | 2024 |
| Sula Construction & Building Ltd | Construction | 2021 |
| Sulis Fire Consultants Limited | Administrative & support | 2019 |
| Summitkey Asset Management Ltd | Real estate | 2026 |
| Sun Screens Limited | Professional & scientific | 1996 |
| Sundial Cottage Care Home Ltd | Health & social care | 2022 |
| Sundial Cottage Rest Home Limited | Health & social care | 2020 |
| Super-Mart Ltd. | Real estate | 1999 |
| Supermart Consultants Limited | Real estate | 1994 |
| Supermart Hednesford Limited | Real estate | 2018 |
| Supermart Retailers Limited | Real estate | 2007 |
| Supermart Stores Limited | Real estate | 2001 |
| Supervision Assured Limited | Administrative & support | 1976 |
| Sustainable Urban Logistics Ltd | Professional & scientific | 2025 |
| Swaffield Close Management Company Ltd | Real estate | 2020 |
| Swan Finance Limited | Financial services | 2017 |